#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>
#include<assert.h>
char* my_strcpy(char* dest,const char* source)
{
	assert(dest && source);
	char* ret = dest;
	while (*dest++ = *source++);
	return ret;
}
int main()
{
	char arr1[20] = { 0 };
	const char* arr2 = "the world";
	printf("%s", my_strcpy(arr1, arr2));                                                                                                                                             my_strcpy(arr1, arr2);
}